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117 lines
3.3 KiB
Plaintext
117 lines
3.3 KiB
Plaintext
= zmq_ctx_get(3)
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== NAME
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zmq_ctx_get - get context options
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== SYNOPSIS
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*int zmq_ctx_get (void '*context', int 'option_name');*
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== DESCRIPTION
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The _zmq_ctx_get()_ function shall return the option specified by the
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'option_name' argument.
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The _zmq_ctx_get()_ function accepts the following option names:
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ZMQ_IO_THREADS: Get number of I/O threads
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~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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The 'ZMQ_IO_THREADS' argument returns the size of the 0MQ thread pool
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for this context.
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ZMQ_MAX_SOCKETS: Get maximum number of sockets
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~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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The 'ZMQ_MAX_SOCKETS' argument returns the maximum number of sockets
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allowed for this context.
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ZMQ_MAX_MSGSZ: Get maximum message size
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~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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The 'ZMQ_MAX_MSGSZ' argument returns the maximum size of a message
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allowed for this context. Default value is INT_MAX.
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ZMQ_ZERO_COPY_RECV: Get message decoding strategy
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~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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The 'ZMQ_ZERO_COPY_RECV' argument return whether message decoder uses a zero copy
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strategy when receiving messages. Default value is 1.
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NOTE: in DRAFT state, not yet available in stable releases.
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ZMQ_SOCKET_LIMIT: Get largest configurable number of sockets
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~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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The 'ZMQ_SOCKET_LIMIT' argument returns the largest number of sockets that
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xref:zmq_ctx_set.adoc[zmq_ctx_set] will accept.
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ZMQ_IPV6: Set IPv6 option
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~~~~~~~~~~~~~~~~~~~~~~~~~
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The 'ZMQ_IPV6' argument returns the IPv6 option for the context.
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ZMQ_BLOCKY: Get blocky setting
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~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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The 'ZMQ_BLOCKY' argument returns 1 if the context will block on terminate,
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zero if the "block forever on context termination" gambit was disabled by
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setting ZMQ_BLOCKY to false on all new contexts.
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ZMQ_THREAD_SCHED_POLICY: Get scheduling policy for I/O threads
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~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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The 'ZMQ_THREAD_SCHED_POLICY' argument returns the scheduling policy for
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internal context's thread pool.
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ZMQ_THREAD_NAME_PREFIX: Get name prefix for I/O threads
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~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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The 'ZMQ_THREAD_NAME_PREFIX' argument gets the numeric prefix of each thread
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created for the internal context's thread pool.
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ZMQ_MSG_T_SIZE: Get the zmq_msg_t size at runtime
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~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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The 'ZMQ_MSG_T_SIZE' argument returns the size of the zmq_msg_t structure at
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runtime, as defined in the include/zmq.h public header.
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This is useful for example for FFI bindings that can't simply do a sizeof().
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== RETURN VALUE
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The _zmq_ctx_get()_ function returns a value of 0 or greater if successful.
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Otherwise it returns `-1` and sets 'errno' to one of the values defined
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below.
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== ERRORS
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*EINVAL*::
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The requested option _option_name_ is unknown.
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*EFAULT*::
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The provided 'context' is invalid.
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== EXAMPLE
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.Setting a limit on the number of sockets
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----
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void *context = zmq_ctx_new ();
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zmq_ctx_set (context, ZMQ_MAX_SOCKETS, 256);
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int max_sockets = zmq_ctx_get (context, ZMQ_MAX_SOCKETS);
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assert (max_sockets == 256);
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----
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.Switching off the context deadlock gambit
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----
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zmq_ctx_set (ctx, ZMQ_BLOCKY, false);
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----
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== SEE ALSO
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* xref:zmq_ctx_set.adoc[zmq_ctx_set]
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* xref:zmq.adoc[zmq]
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== AUTHORS
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This page was written by the 0MQ community. To make a change please
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read the 0MQ Contribution Policy at <https://zeromq.org/how-to-contribute/>.
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